


Study Buddies

by audrey1nd



Category: Life with Derek
Genre: College, Cunnilingus, F/M, Getting Together, Oral Sex, Realization, Step-siblings, Studying
Language: English
Status: Completed
Published: 2015-06-28
Updated: 2015-06-28
Packaged: 2018-04-06 14:06:44
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,533
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/4224603
Author URL: https://archiveofourown.org/users/audrey1nd/pseuds/audrey1nd
Summary: <blockquote class="userstuff">
              <p>Derek knows exactly how to get Casey to help him study. He just didn't count on how what she would ask for in return would make him feel.</p>
            </blockquote>





	Study Buddies

**Author's Note:**

  * For [emef](https://archiveofourown.org/users/emef/gifts).



> For emef, but also kind of written with [bessyboo](http://archiveofourown.org/users/bessyboo) in mind since it was her birthday while I was finishing this up. Also because she made us all watch and made me realize there needed to be more fic in this fandom.

Derek sighed as he pushed himself away from his desk and stood up, stretching as much as his tiny dorm room would allow him to. Derek was just glad he’d managed to get a single. The doubles were barely larger than his room. He couldn’t fathom having to share such a small space with another person. At least, not without sharing beds. He chuckled to himself, thinking about all the girls he’d met during orientation week. Casey had scoffed at him with her usual disapproval the first night, but he hadn’t seen her much since then except at a party where she was all wrapped up in some guy. Derek had of course come over and introduced himself. He was just making sure that he was a decent guy, especially after everything Casey had gone through with Truman. That was all. He definitely had not been jealous.

She’d also joined a dance troupe as an extracurricular and Derek had gone with some guys from the hockey team, but she’d been so busy after the show with her own friends that Derek hadn’t felt right interrupting.

But he definitely did not feel any guilt about calling her now. Derek smirked as he opened up his phone and called her.

“Casey,” he drawled in his usual confident tone. “You’re taking psych this semester right?” Derek let Casey start in on how of course she was, it was a famous class and part of their requirements before interrupting to say “Great! Me too. Except I had to miss last class because of hockey practice. An excused absences cleared beforehand, of course, but unfortunately that means I have no one else to turn to for notes so I can prepare for the midterm next week.” Derek might be asking Casey for a favor, but he knew by appealing to her keener self, she would probably feel like she was getting the upper hand by helping him out.

He heard her take a deep breath and the flipping of paper in the background as he waited for her response. “Lower library, 7 o’clock, after dinner, tomorrow night, bring your textbook and notes.” She paused again and Derek knew this was her preparing to order him to do something she knew he wouldn’t want to do. “And I get to come to one of your hockey games and come to a party thrown by the team.”

“Really Casey, a hockey party? Since when is that your scene?”

Casey sighed in return. “You don’t know what my scene is anymore Derek. I haven’t seen you since orientation. But if you must know, some of your teammates are in my classes and invited me to the party this weekend,” she said in a haughty tone of voice.

“And do they know you’re my stepsister?” Derek smiled to himself. This might get him homework help for the entire year if he played it right.

Casey sighed. “No, as we agreed, separate friends and separate lives. They just know that we went to high school together.” She paused. “They’re always asking me for stories. I think they might be hoping for something embarrassing. Imagine what they’d want to know if they knew I was your stepsister.”

Damn, she was good. Derek was going to have to play this very carefully.

“Fine, you can come. By the way, some of us went to your dance performance, so they might mention it.”

“Derek Venturi, voluntarily going to a dance performance? I’m shocked. First wanting to study, now this? Maybe you really have turned a new leaf.”

“Hey, who said this was a permanent thing? I just missed a class.” No need for her to think that he was eager for her help. Now if he asked again she would think she was proving him wrong.

“Fine, whatever,” Casey sighed. “I’ll see you tomorrow. You better not be late.”

 

“Shit,” Derek hissed as he saw the time. He shoveled food in his mouth quickly. Casey would kill him if he was late.

“Dude, you got a hot date or something?” his friend Trevor asked as he stood up.

Derek smirked at him. “Something like that.”

 

Derek breathed a sigh of relief as he entered the part of the library that Casey had specified. It was mostly full of book stacks, but there were a few armchairs arranged around small tables every so often, and only one of them was occupied so far. No wonder Casey liked it. She could study to her heart’s delight and probably didn’t have to worry about being interrupted.

Derek took in the whole area. It would also make for quite a nice rendezvous spot. Casey was always helping Derek in unexpected ways.

Which of course was when he heard Casey hiss “Derek,” as she stumbled into the library, in her dance gear, a fine sheen of sweat on her brow. “Sorry, practice ran late. Come on, let’s go before my favorite spot gets taken. 

 

It turned out that Casey’s favorite spot was even more secluded.

“Cozy,” Derek said as he took off his backpack and dropped down into a cushy armchair.

“Yeah, well, this way I can study without having to break for dinner or snacks,” Casey blushed as she took a wrapped sandwich out of her backpack.

“You little rule-breaker,” Derek teased.

“It’s not like I’m going to be hurting any of their books or making a mess,” Casey said defensively. “Now take out your notes, I have a checklist of what’s supposed to be on the midterm.”

 

Derek yawned and stretched backwards in his chair, shirt riding up, revealing his stomach. He felt Casey’s eyes on him. “What, am I making too much noise?”

“No,” Casey quickly looked away, blushing. She stood up. “I’m going to get some coffee, you want anything?”

“I’ll take some coffee too. Two sugars – “ he cut off as Casey started to say the same thing.

“I know how you take your coffee,” she huffed. “Now stay here and review. I’ll be quizzing you when I get back.”

 

It was Saturday night and Derek was celebrating his team winning, and getting three points himself, at the usual post-game party. Casey had yet to arrive, but he was keeping an eye out for her. It was kind of nice having her at his game, cheering on him and his teammates. Maybe he’d keep their little arrangement going until the season ended. Good grades and good hockey and Casey thinking he was doing her a favor was always a good thing.

Derek heard a shout of “Casey” and turned away from the girl he was flirting with to see both Trevor _and_ Greg greeting Casey. Greg had his arm around her waist and Trevor was handing her a drink. Casey smiled gratefully at Trevor as she took the drink from him and sipped, moving away from Greg. Clearly Casey was here to hang out with Trevor, and not Greg. Derek smirked to himself, Greg was kind of an asshole. He was glad Casey had the good taste to like his friend who just happened to be gay. It meant that Derek could enjoy his night without having to worry about seeing Casey make goo-goo eyes at one of the guys on his team.

He turned back to the girl he was talking to. She flicked her brown hair over her shoulder as she complimented him on his game.

“I’ve been to every game so far this season and this was by far your best,” she said.

Derek smiled down at her. “Oh really? Well I’ve just been warming up. Make sure you keep coming because it’ll only get better.”

“Oh, I will,” she said with a flirty smile. “I just love the athleticism of hockey. The speed and force you skate with. The way you control the puck,” her hand rested on Derek’s shoulder and slowly drifted down to his hand as she spoke. “Do you want to get out of here?” She batted her eyelashes at him as she took his hand.

But just at that moment Trevor dragged Casey out onto the dance floor, her hair floating past him as they went by and he turned his head to see the two of them dancing enthusiastically – and very well – to the music. He turned back to, her name was Erica, wasn’t it, but she had gone. Derek shrugged. Plenty of other girls. And besides, the night was only getting started, why would he want to leave so early with someone he’d only just met?

Derek leaned against the wall and drank his beer, surreptitiously watching Trevor and Casey dance together. Derek smiled into his cup as he took another sip. She was clearly enjoying herself. Having Casey at hockey parties could only work to his advantage.

But just as Derek was trying to think of what other favors he could get out of Casey, he saw Greg move behind Casey and try to dance with her. She deftly moved away from him and continued dancing with Trevor. But Greg clearly hadn’t gotten the hint or was too drunk to do so and he tried again, this time putting his hands on Casey’s hips and moving in close behind her.

She made a face at Trevor and tried to move away from Greg again, but he just moved with her. Trevor hadn't noticed. He was just happily dancing to the music, drinking from his cup.

Derek threw out his now empty cup and moved towards Casey.

“Casey!” he yelled over the music. “So good to see you.”

Casey, seeing his appearance as the rescue it was, lunged into his arms, breaking Greg’s grip on her hips.

“Derek!” she cried out. “Long time no see! Great game today.” She broke off the hug and maneuvered them away from the dance floor and Greg.

When they were in a quiet corner of the kitchen Casey gave him another hug. “Thanks for that,” she said as she drew back. “Ugh, Greg is a total creep. I did _not_ come here to hang out with him. Trevor invited me and has been bugging me to hang out with him other than editing our papers together. A guy like Greg is not my kind of guy.”

“He’s not one of my favorite people either,” Derek replied and took a sip of beer. Casey’s face was shiny with sweat from dancing as she smiled up at him. His stomach did a flip and he found himself leaning down to kiss her. Casey wrapped her arms around his neck and kissed him back for a moment before drawing back. 

Her eyes were wide as she looked into his and touched her fingertips to her lips before surging forward and kissing him again. Derek’s arms came around her back, pressing them together as they kissed, one of his hands stroking the back of Casey’s neck. Casey arched against him as her mouth opened underneath hers and Derek slipped his tongue into her mouth. Derek didn’t know how long they stood there making out before they were interrupted by a random kid bumping into them, hipchecking Derek.

They broke apart and stared at each other for a minute, breathing heavily. 

“So uh, you want to get out of here?” Derek asked awkwardly, running a hand through his hair.

“Yeah,” Casey answered breathlessly. She grabbed his hand and pulled him through the house behind her towards the exit. When she passed Trevor, she clapped him on the shoulder and whispered something in his ear, and he nodded with a big smile and winked at Derek.

HOLY FUCKING SHIT. Casey was not the girl he thought she was if even her random friends knew she was about to get laid. 

Derek smiled. He’d always found her attractive, but had always been too annoyed by her nagging to actually do anything about it. Sometimes he’d thought about it, especially when he saw her in the morning in her cute little pj sets, but it just hadn’t seemed like a good idea. But _here_ , here they were just two friends from high school as far as anyone knew. 

The cooler air outside was refreshing after the heat of the house. They settled into a slow walk, holding hands as they headed back to campus. Derek paused when they reached his dorm, but Casey just tugged him towards the door and they headed inside.

He opened the door to his dorm room with a flourish, holding it open for Casey and thanking the gods above that he’d cleaned his room after the game.

She entered with trepidation, she _had_ lived with him after all, and nodded with a pleased smile. He shut the door behind him, leaning against it and looked at her for a minute. She was breathtaking in the tight sparkly top she was wearing with tight jeans. 

Casey looked back at him and smiled before moving towards him, pushing him against the door with a hand on his shoulder and reaching up to kiss him, her arms going around his neck.

They kissed for a minute before Derek lifted her up, causing Casey to gasp before she wrapped her long toned legs around him. Derek moved them towards the bed and gently laid Casey down, leaning over and kissing her again, before slowly moving down her neck to her collarbone, his hands on her waist, gently stroking the skin right under the hem of her shirt.

With a moan, Casey pulled him forward on top of her, breaking contact as she pulled his shirt off and she sat up, legs in between his, staring at him admiringly. “You know, I don’t think I ever really appreciated that you play hockey before tonight,” she teased as her hand drifted down his chest to his hip, where she played with the waistband of his pants.

“Fuck Casey, since when are you such a tease?” Derek gasped, his hands going underneath her shirt and pushing it up as he resumed kissing her neck, working on a hickey right where her neck met her shoulder.

Casey gasped underneath him as his hands reached her breasts and she pulled her shirt off over her head, before reaching behind her to remove her bra. “Who are you calling a tease?” she smirked as she pulled him forward by the face to kiss him, their bare chests meeting. Derek gasped into Casey’s mouth at the feeling of their skin touching.

Casey grinned at him as they parted for breath and unbuttoned his pants and then her own, wiggling out of them from underneath him. Derek groaned at the feel of her as he pushed his own pants down. His response made Casey grin wickedly at him. Well, if she wanted to make it a challenge, Derek was definitely up to that challenge.

“So that’s how it’s gonna be, eh?” he laughed.

“As if it’s ever been any other way,” Casey scoffed.

“Well in that case…” Derek trailed off as he took one of Casey’s nipples into his mouth and tweaked the other.

“Is that the best you can do?” Casey gasped in response.

Derek smirked. In one swift motion he moved down Casey’s body, pulling her underwear down. Derek stroked at her clit with his fingers before licking up her folds, causing Casey’s hips to buck in response. “Does that answer your question?” Derek purred. God she was wet.

“Why don’t you get me off first and then I’ll judge,” Casey challenged, her eyes gleaming.

Derek just narrowed his eyes in response. He moved his fingers over her clit again and she moaned in response. Derek smirked and dipped his head back down, breathing in her scent. It was both familiar and new. It smelled like Casey, but a little stronger and saltier. It was new and Derek loved using new information about Casey to drive her wild. 

He slowly slid his finger down and stroked Casey’s slit, before pushing in, his breath falling hot on her pussy as he pumped first one, then two, fingers in and out.

“Come on, I need more,” Casey whined as he ghosted his thumb back over her clit.

He stopped moving, fingers still in place, and looked up at her, “I always did love it when you begged.”

Casey glared at him. “I was _not_ begging. That was an order. Now can you finish the job, or do I need to go back to mine and get my vibrator out?”

“Oh, I can finish the job,” Derek replied haughtily, curling his fingers as he started moving them again. His licked at her clit softly, drawing a whine out of Casey as her hips arched up and her legs started shaking. Derek put his arm over her hips to hold her down and pulled his fingers out, replacing them with his tongue and rubbing at her clip with his slick fingers.

Casey let out a loud moan followed by a whimper of “Der-ek” the syllables drawn out like she did when she was mad at him. But clearly he’d done a good job, as he rubbed slowly until her legs stopped shaking.

Sweat glistened on Casey’s chest, which was moving rapidly as she caught her breath.

Derek moved up the bed to lie beside her, leaning on his arm and looking down at her. He licked across her collarbone before kissing up her neck, just grazing her skin with his teeth, before planting a soft kiss on her now softly parted mouth. “So, how’d I do?”

Casey laughed, “You know exactly how you did.”

“Well I don’t know. How do I compare?” Derek hoped that the only guy she had to compare him to was Truman, who had probably been terrible, but there had been that one weekend when Sam and Casey had both disappeared and Sam only gave vague answers on what he’d been doing that weekend.

“Not the worst I’ve had.”

Derek opened his mouth to protest, but Casey started giggling immediately. “Oh wow, your face!” she sputtered out, hand over her mouth as she shook with laughter. Her eyes softened. “Come here,” she whispered, pulling him down on top of her for a kiss. Casey’s hands moved down his back as they kissed, squeezing his ass for a moment before moving up and slipping inside his boxers, thumbs hooking over the waistband and pushing them down.

“Do you have a condom?” she whispered in his ear, and Derek reached a hand out to his nightstand, groaning as Casey took his dick in her palm, stroking up and down.

Derek sat up, kicking his boxers off and Casey’s eyes roved over his body appreciatively as he opened the condom he’d grabbed and rolled it on.

“So, uh” Derek paused awkwardly. He’d known Casey for years, but this was something new and he wasn’t really sure how to proceed.

Casey sighed dramatically. “The great Derek Venturi, uncertain about what to do in bed? I’m shocked,” Casey mocked as she wrapped a leg around his hips and pulled him down, kissing him. She took his penis in her hand and stroked before guiding him in.

Derek gasped as he entered her. This was even better than he’d imagined, seventeen and lying in bed at night, fantasizing about her. She was warm and alive all around him, making little encouraging sounds as he pumped in and out, peppering her chest with wet, open-mouthed kisses. 

Derek was getting close, this was the height of his high school fantasies after all, so he hiked Casey’s leg up higher to get a better angle before slipping a hand in between them and rubbing at her clit. Casey arched in reaction. “Yes, that’s it. Fuck – come on,” she gasped out.

“Yeah, come on,” Derek breathed. “Open your eyes. Look at me,” he whispered. Casey did so, pinning him with her piercing blue eyes as he got closer, hips losing their rhythm. But he couldn’t lose this competition so he slowed down and concentrated on Casey’s clit until her legs started shaking, the one around his hip gripping even tighter. He could feel how close she was and he concentrated on keeping up his rhythm even as he chased his own end. Finally he felt Casey coming, softer this time with a series of gasps instead of moans, and he took that as his own cue.

 

Derek stroked Casey’s hair as he lay on his side beside her, enjoying the way she looked in his bed, wearing one of his hockey shirts. His other hand was under the covers, stroking at her bare hip under the shirt. 

“I guess that was okay. We could do it again sometime,” Casey shrugged, mouth curled in a small smile. “Depends on how you do on your midterms.”

Derek groaned. Classic Casey. Trust her to bring up grades after sex.

“Does that mean you’ll help me study for my finals? Will I get a _special_ Christmas present if I do well?”

“Der-ek!” she groaned in that special way of hers, hitting his arm softly as she laughed.

Derek smiled and kissed her softly on the mouth before reaching over to turn off the light and curl around her.


End file.
